DE2606358A1 - STABILIZER SYSTEMS MADE FROM TRIARYLPHOSPHITES AND PHENOLS - Google Patents

Description

Stabilizer systems made from triaryl phosphites and phenols

The present invention relates to the use of stabilizer systems made from triaryl phosphites and phenols to stabilize polyolefins against thermo-oxidative damage, as well as the polyolefins stabilized with them.

It is known to use triesters of phosphorous acid as stabilizers to be used in polyolefins. Likewise, e.g. in J. Voigt, "The stabilization of plastics against light und Wärme ", 1st edition. Springerverlag 1966, page 323, the combination of phosphorous acid esters with other antioxidants put down as their preferred form of application,

In particular, it is known from US Pat. No. 3,558,554 that the three-part combination "phosphite containing aryl groups" - "phenolic Compounds "- to use" thiodialiphatic esters "in polyolefins.

There are many among the "aryl group-containing phosphites" mixed substituted (asymmetrical) phosphites, i.e. those that enter into intermolecular transesterification reactions, are liquid and hydrolyze easily, resulting in poor storage stability and poorly producible effectiveness leads. In addition, when thiodialiphatic ester is added, under

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Processing conditions often observed discoloration.

From GB 1,078,772 it emerges that the mixture of aryl-containing phosphates with o-substituted phenols in polyolefins is particularly important shows good stabilizing effectiveness. The o-substituent in the phenolic component is essential for good effectiveness blamed.

US 3,533,989 also describes the special two-way combination of 2,6-ditert.butyl-4-methylphenol with Polygard (Tris-p-nonylpheny! Phosphite) described as a stabilizer for polyolefins. In the same patent the use of tris (2-tert-butyl-4-methylphenyl) phosphite, optionally in combination with Polygard. Both combinations contain polygard, Which, like the above-mentioned phosphites, is an oily liquid with the disadvantages described.

It was non-surprisingly found to be a limited class of symmetrical triaryl phosphites of the general formula I

(D

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wherein R _{1 is} tert-butyl, 1,1-dimethylpropyl, cyclohexyl or phenyl and one of R ₂ and R _{3 is} hydrogen and the other is hydrogen, methyl, tert-butyl, 1,1-dimethylpropyl, cyclohexyl or phenyl, in combination with phenolic antioxidants develop a particular effectiveness in polyolefins against degradation and crosslinking reactions, as they normally occur in the processing of polyolefins.

• This particular effectiveness manifests itself in particular in the excellent colorlessness of the resulting polymer, which represents an advance over the three-way combination described in US Pat. No. 3,558,554 as prior art. In addition, there is better effectiveness compared to the combinations described in US Pat. No. 3,558,554 with asymmetrical ones Phosphites or the combinations described in US Pat. No. 3,553,989 with tris-p-nonyl-phenylphosphite achieved.

The compounds of formula I can - together with one or more of the phenolic compounds - can be used individually or in combination with one another. the Phosphites which can be used according to the invention are mostly crystallized Solid bodies, which are also resistant to hydrolysis, compared with the wide range of phosphites known today, are particularly stable.

In Formula I they have. Symbols prefer the following meaning:

R: tert-butyl, I, 1-dimethylpropyl, one

from

R ₉ and R ₃ : hydrogen and the other hydrogen,

Methyl, tert-butyl or 1,1-dimethylpropyl,

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Particularly preferred mean

R ^ tert-butyl and one of R ^ and R ~

Hydrogen and the other hydrogen methyl or tert-butyl.

Particularly suitable compounds of formula 1 are e.g.

Tris (2,5-di-tert-butylphenyl) phosphite Tris (2-tert-butylphenyl) phosphite Tris (2-pheny! Phenyl) phosphite

Tris [2- (1,1-dimethylpropyl) phenyl] phosphite Tris- [2,4-di- (1,1-dimethylpropyl) phenyl] phosphite Tris (2-cyclohexylphenyl) phosphite Tris (2-tert-butyl-4-pheny! Phenyl) phosphite

or in particular also

Tris (2,4-di-tert-butylphenyl) phosphite.

Examples of phenolic compounds include:

1. Simple 2,6-dialkylphenols , such as

2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol or 2,6-di-tert-butyl-4-methoxyphenol.

2. Bisphenols , such as

2,2'-methylenebis (6-tert-butyl-4-methylphenol), 2,2'-methylenebis (6-tert-butyl-4-ethylphenol), 2,2'-methylenebis [4-methyl-6- (oc-methylcyclohexyl) phenol] , l, l-bis (5-tert-butyl-4-hydroxy-2-methylphenyl) butane, 2,2-bis- (5-tert-butyl-4-hydroxy-2-methylphenyl) butane, 2,2-bis- (3,5-di-tert-butyl-4-hydroxyphenyl) -propane, 1,1,3-tris- (5-tert-butyl-4-hydroxy-2-methyl-

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phenyl) butane, 2,2-bis (5-tert-butyl-4-hydroxy-2-methylphenyl) -4-n-dodecylmercapto-butane, 1,1,5,5-tetra- (5-tert. butyl-4-hydroxy-2-uiethylphenyl) pentane, ethylene glycol bis [3,3-bis (3 ¹ -tert.butyl-4 ^T -hydroxyphenyl) butyrate], 1,1-bis (3,5- dimethyl-2-hydroxyphenyl) -3- (n-dodecylthio) -butane or 4,4 ^f -thiobis- (6-tert-butyl-3-methylphenol).

3. Hydroxybenzyl aromatics , such as

1,3,5-tri- (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene; 2,2-bis- (3,5-di-tert-butyl-4-hydroxybenzyl) malonic acid dioctadecyl ester; 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate or 3,5-di-tert-butyl-4-hydroxybenzyl-phosphonic acid diethyl ester.

4. Amides of ß- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid ) such as

1,3,5-tris- (3,5-di-tert-butyl-4-hydroxyphenyl-propionyl) -hexahydro-s-triazine, N, N'-di (3,5-di-tert-butyl-4-hydroxyphenyl-propionyl) -hexamethylenediamine.

5. Esters of ß- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid with monohydric or polyhydric alcohols, such as, for example, with methanol, octadecanol, 1,6-hexanediol, ethylene glycol, thiodiethylene glycol, neopentyl glycol , Pentaerythritol, tris-hydroxyäthy1-i s οcyanurat.

6. Spiro compounds , such as

diphenolic spiro diacetals or diketals, such as in 2,4,8,10-tetraoxaspiro- [5,5] -undecane substituted by phenolic radicals in the 3-, 9-position, such as, for example, 3,9-bis- (3,5-ditert .butyl-4-hydroxyphenyl) -2,4,8,10-tetraoxaspiro- [5,5] -undecane, 3,9-bis- [1,1-dimethyl-2 (3,5-di-tert-butyl-4-hydroxyphenyl) -ethyl] -2,4,8,10-tetraoxaspiro- [5,5] undecane.

ORIGINAL INSPECTED

G 0 9 B 3 6/0 9 6 8

Particularly preferred phenolic compounds are

1,3,5-tri- (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene

Pentaerythritol tetra [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]

/3-(3,5~Di-tert.butyl-4-hydroxyphenyl) propionic acid n-oetadecyl ester

Thiodiäthylenglykol- _/ '5- _{[4-hydroxy-3-J} 5 dirtert.butyl-phenylJ-propionate

2,6-di-tert. -but3rl-4-methyl-phenol

3,9-bis [1,1-dinethyl-2 (3,5-diterC.butyl-4-hydroxyphenyl) -thylI-2,4,8,10-tetraoxaspiro- [5,5] -undecane ..

The compounds of the formula I can be prepared according to known methods Methods take place, for example by reacting a phenol of the formula II

OH

(ID

with phosphorus trichloride without a solvent at 20-25O ⁰ C, or in an inert, aprotic solvent in the presence of an organic base, or by reacting a compound of

Formula II with triphenyl phosphite, preferably without a solvent, in the presence of a basic catalyst.

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The resulting compounds are recrystallized in cleaned with a suitable solvent (mixture).

The following polyolefins, for example, can be stabilized with the stabilizer mixture according to the invention:

1. Polymers that are made up of monounsaturated hydrocarbons derive, such as polyolefins, such as polyethylene, low and high density, which optionally can be crosslinked, polypropylene, polyisobutylene, polymethylbutene-1, Polyenethylphenten-1,

2. Mixtures of the homopolymers mentioned under 1, such as e.g. Mixtures of polypropylene and polyethylene, polypropylene and polybutene: en-1, polypropylene and polyisobutylene. .

3. Copolymers of the homopolymers mentioned under 1 on which they are based Monomers, such as ethylene-propylene copolymers, Propylene-butene-1 copolymers, propylene-isobutylene copolymers, Ethylene-butene-1 copolymers, as well as terpolymers of ethylene. and propylene with a diene such as hexadiene, Di-cyclopentadiene or ethylidene norbornene.

The inventive stabilizer mixture is in a Concentration of

0.005 to 5%, preferably 0.01 to 1%, particularly preferably 0.05 up to 0.5%, calculated on the material to be stabilized, remains. The triaryl phosphite and the phenolic antioxidant are incorporated in a ratio of 10: 1 to 1: 5, preferably 5: 1 to 1: 2, and in particular 3: 1 to 1: 1. The Einar-

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processing can be done by various methods, for example by dry mixing the polymer with at least one of the compounds according to the invention and a phenolic Antioxidant and subsequent processing in the kneader, mixing roll mill or extruder. The additives mentioned can also be applied to the polymer in the form of a solution or dispersion the solvent is subsequently evaporated.

As examples of further additives that, together with the inventive Combination can be used, are to be mentioned:

1. Aminoaryl derivatives , such as

Phenyl-1-naphth3 ^T lamin, phenyl-2-napththylamine, N ₅ N ¹ -di-phenyl-p-phenylenediamine, N ₅ N ¹ -di-2-naphthyl-pphenylenediamine, N ₅ N ¹ -di-2-naph ': hyl-p-phen3 ^T lendiainin ₅ Ν, Ν ¹ -di-sec.butyl-p-phenylenediamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline 6-dodecyl-2, 2 ₅ 4 x tri-Inethyl ~ l, 2 ~ dih3''drochinolin, Mono.r and Dioctyliminodibenzyl, polymerized 2, _2} 4-trimethyl · -l _J 2-dihydro ■ quinoline. ■ ■ _ Octylated diphenylamine, nonylated diphenylarain, H-phenyl'-N ¹ -cyclohexyl-p-phenylenediamine, N-phenyl-N '.isoprop3 ⁷ lp-phenylenediamine, Ν, Ν ¹ -di-sec.octyl-p-phenylenediamine , N-phenyl-N'-see.octyl-p-phenylenediamine, Ν, Ν ¹ -Di- (1,4-dimethylpentyl) -p-phenylenediamine, N ₅ N ¹ -dimethyl-Ν, Ν ¹ -di- ( sec.octyl) -p-phenylenediamine, 2,6-dimethyl-4-methoxyaniline, 4-ethoxy-N-sec.butylaniline, diphenylamine-acetone condensation product, aldol-1-naphthylamine, phenothiazine.

When using this group, there is discoloration to count «

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260S358

2. UV absorbers and light stabilizers

2.1. 2- (2'-Hydroxyphenyl) -benztrlazoles , such as the

5'-methyl-, 3 ¹ , 5'-di-tert-butyl-, 5 ^f -tert.butyl-, 5 ¹ - (1,1,3,3-tetramethylbutyl) -, S-chloro-3 ¹ , 5'-di-tert. butyl-, 5-chloro-3'-tert-butyl-5 ¹ -methyl-, 3 ^f -sec.Butyls '-tert .butyl-, 3' -cc-methylbenzyl-5 ¹ -methyl-, 3 ^! - <x-methylbenzyl-5'-methyl-5-chloro-, 4'-hydroxy-, 4 ^f -methoxy-, 4'-octoxy-, 3 ¹ , 5'-di-tert.atnyl-, 3 ¹ - Methyl-5'-carbomethoxyethyl-, 5-chloro-3 ^r , 5'-di-tert-amyl derivative.

2.2. 2,4-Bls- (2'-hydroxyphenyl) -6-alkyl-s-triazines , such as the

6-ethyl-, 6-heptadecyl-, 6-undecyl derivative.

2.3. 2-hydroxybenzophenones , such as. the

4-hydroxy, 4-methoxy, 4-octoxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy-, 4,2 ', 4 "-trihydroxy-, 2'-hydroxy-4 , 4'-dimethoxy derivative.

2.4. 1,3-Bls- (2 ^f -hydroxybenzoyl) -benzenes , V7ie, for example 1,3-bis- (2'-hydroxy-4 ¹ -hexyloxy-benzoyl) -benzene, 1,3-bis- (2'-hydroxy -4 ¹ -octyloxy-benzoyl) -benzene, 1,3-bis- (2 ¹ -hydroxy-4 ¹ -dodecyloxy-benzoyl) -benzene.

2.5. Esters of optionally substituted benzoic acids, V7ie, for example

Phenyl salicylate, octylphenyl salicylate, dibenzoyliresorcinol, Bis (4-tert-butylbenzoyl) resorcinol, benzoylresorcinol, 3,5-Di-tert-butyl-4-hydroxybenzoic acid-2,4-di-tert. butylphenyl ester or octadecyl ester or -2-methyl-4,6-di-tert-butylphenyl ester.

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2.6. Acrylates , such as

a-Cyano-β ^ -diphenylacrylic acid ethyl ester or isooctyl ester, cc-carbomethoxy-zinitic acid ethyl ester, a-cyano-fjmeth} ^T lp-methoxy-citric acid methyl ester or -butyl ester, N - (/ 3-carbomethoxyvinyl) -2-methyl -indoline.

2.7. Nickel compounds , such as

Nickel coraplexes of 2,2'-thio-bis- [4- (l, l, 3,3-tetramethyIbuty1) -phenol], such as the 1: 1 or 1: 2 complex, optionally with additional ligands such as n- butylamine, triethanolamine or N-cyclohexyl-di-ethanolamine, nickel complexes of bis [2-hydroxy-4- (l, 1,3,3-tetrameth3 ^r lbutyl) -phen3 '·!] - sulfonic, such as the 2: 1 -Complex, optionally with additional ligands such as 2-ethylcaproic acid, nickel dibutyldithiocarbamate, nickel salts of 4-hydroxy-3 _$ 5-di-tert-butylbenzyl-phosphonic acid monoalkyl esters such as methyl, ethyl or butyl esters, nickel complexes of ketoxites such as 2-hydroxy 4-meth3 ^ 1-phenyl-undecyl ketone oxime, nickel-3,5-di-tert. butyl 4-hydroxybenzoate, nickel isopropyl xanthate.

2.8. Sterically hindered amines , such as, for example, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, bis (2.2,6,6-tetramethylpiperidyl) sebacate, 3- n-Octyl-7,7,9,9-tetramethy1-1,3,8-triaza-spiro [4,5] decane-2,4-dione.

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26 (36358

2.9. Oxalsnurediamide , such as · '

4,4'-di-octyloxy-oxanilide, 2,2'-di-octyloxy-5,5'-di-tert-butyl-oxanilide, 2,2'-di-dodecyloxy-5,5'-di-tert. butyl-oxanilide, 2-ethoxy-2'-ethyl-oxanilide, N, N ¹ -bis- (3-dimethylaminopropyl) -oxalamide, 2-ethoxy-5-tert. butyl-2 ^f -ethyl-oxanilide and its mixture with 2-ethoxy-2 '~ ethyl-5,4'-di-tert-butyl-oxanilide, mixtures of ortho- and para-methoxy and of o- and p- Ethoxy-disubstituted oxanilides.

3. Metal deactivators , such as

Oxanilide, isophthalic acid dihydrazide, sebacic acid bisphenyl hydrazide, bis-benzylidene-oxalic acid dihydrazide, N, N'-diacetyl-adipic acid dihydrazide, N, N ¹ -bis-salicyloyl-oxalic acid dihydrazide, N, N 1 -bis-salicyloylhydrazine, N, N ¹ -bis-salicyloylhydrazide (3,5-di-tert-butyl-4-hydroxyphen3 ^T lpropionyl) hydrazine, N-salicyloyl-N'-salicylalhydrazine, 3-salicyloylamino-1,2,4-triazole, N, N ¹ -bis-salicylol- thiopropionic acid dihydrazide. -.

4. Basic costabilizers , such as

Alkali and alkaline earth salts of higher fatty acids, for example Ca stearate, Zn stearate, Mg behenate, Ca ricinoleate, K-PaImitate.

5. Clumping agents , such as

4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid. "

6. Other additives , such as

Lubricants, for example particularly preferably "stearyl alcohol, fillers, carbon black, asbestos, kaolin, Tallc, glass fibers, pigments, optical brighteners, flame retardants, antistatic agents. _M

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The invention is described in more detail in the following examples. Percentages (%) therein mean percentages by weight, calculated on the material to be stabilized.

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Example I.

100 parts of unstabilized high-density polyethylene with a molecular weight of about 500,000 ("Lupolen · 5260 Z" in powder form from BASF) are mixed with 0.05 parts of pentaerythritol tetra [3- (3,5-di-tert .butyl-4-hydroxyphenyl) propionate] and 0.1 part of a stabilizer from Table 1 or 2 below, dry mixed. The mixtures are kneaded in a Brabender plastograph at 220 ⁰ C and 50 rpm for 20 minutes. During this time, the kneading resistance is continuously registered as torque. As a result of the crosslinking of the polymer, a rapid increase in torque takes place over the course of the kneading time after initial constancy. The effectiveness of the stabilizers is expressed in an extension of the constant time.

The mixtures are then removed from the plastograph and pressed in a plate press at a plate temperature of 260 ° into plates 1 mm thick, which are visually assessed for their color appearance. For the color assessment of Tables 1 and 2 an empirical color scale was used in which 5 colorlessness, 4 a just perceptible, slight discoloration 3,2,1 and <1 a successively stronger discoloration.

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Table 1

Effectiveness of the stabilizer combinations according to the invention

Phosphite stabilizer Time in minutes
until change
of the torque Color berutei Iu η g
the
Press plates None
Tris- (2,4-di-tert-butyl-
phenyl) phosphite
Tris- (2-ter.t .butyl-4-
niethylphenyl) phosphite
Tris- (2-tert-butyl-5-
methylphei ^ l) phosphite 3 ^{1 year}
10
10 ¹ ^
9 5
4-5
4th
4th

Table 2. .

Effectiveness of the unsymmetrical ■ yriphosphites described in US 3 55B 554

Phosphite stabilizer Time in minutes
until change
of the torque Color distribution
the ^; ·
Press plates None
Di-n-butyl- (2-tert.
butyl-4-methylphenyl) -
phosphite
Di-phenyl- (2-tert.
butyl-4-methylphenyl) -
phosphite
Di-n-butyl- (2,6-di-tert.
butyi-4-methylphenyl) -
phosphite 3 ^1/2
4th
4 ^X / 2 5
4th
4-5
2 (stained,
inhorr.og en)

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From the data in Tables 1 and 2 show that the triaryl of formula I in Table 1 in polyolefins ι eir develop particularly good activity compared to in Table 2-to-find comparable products. In particular, the use of dilauryl thiodipropionate leads to a plastic compound with poor color properties.

Example II

100 parts of unstabilized high density polyethylene having a molecular weight of about 500 ¹ OOO ( "Lupolen 5260 Z" in powder .form BASF) are dry mixed with each of 0.1 parts of dilauryl thiodipropionate and the stabilizers of Table 3 below. The mixtures are "for 20 minutes in a Brabender plastograph at 220 ⁰ C and 50 rpm. During this time the kneading resistance is recorded continuously as torque. As a result of crosslinking of the polymers he & lgtim the course of the kneading time after initial Konstanz a rapid increase in the torque. The .Wirksamkeit of the stabilizers is expressed in a lengthening of the constant time. the mixtures are then removed from the Brabender and pressed in a platen press at 260 ⁰ C plate temperature into 1 mm thick plates, ■ which can be visually judged by their color appearance. For the color assessment of the table 3 an empirical color scale was used, in which 5 colorlessness, 4 a just perceptible, slight discoloration; 3, 2, 1 and 1 mean successively stronger discoloration.

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Table 3

Share stabilizer time in minutes until the torque changes

Assessment of the press plates

0.05 part of pentaerythritol tetra-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate

0.05 part of pentaerythritol tetra-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate

+ 0.1 part tris (2- 'tert-butyl-4-methylphenyl) phosphite

0.05 part of pentaerythrit-t-tetra-3- (3,5-di-tert-butyl-4-hydroxy-. phenyl) propionate

+ 0.1 part tris (2,4-ditert.buty! Phenyl) phosphite

0.05 part 1,1,3-tris - ($ - tert-butyl-4-hydroxy-2-methylphenyl) butane

0.05 part of 1-, 1,3-tris (5-tert-butyl-4-hydroxy-2-methylphenyl) butane

+0.1 parts tris (2-tert-butyl-4-methylphenyl) phosphite

0.05 'part 2,6-di-tert. butyl-4-methylphenol

0.05 part of 2,6-di-tert. butyl-4-methylphenol

+ 0.1 part tris (2- ■ tert-butyl-4-ir.e.thylphenyl) phosphite 2 1/2

5 1/2

. 5

10 1/2

<x

-6- / 09 6 ^; 8th"

The results show that regardless of the antioxidant used, when dilauryl thiodipropionate is also used, a Plastic compound with poor color properties and for Part of bad constant times is obtained.

Example III

100 parts of unstabilized high density with a molecular weight of about 500 ¹ OOO ( "Lupolen 5260 Z" in powder form from BASF) polyethylene are mixed with the stabilizers of Table 4 below at the concentrations indicated 'dry. The mixtures are kneaded in a Brabender plastograph at 220 ⁰ C and 50 rpm for 20 minutes. During this time, the kneading resistance is continuously registered as torque. As a result of the crosslinking of the polymer, the torque increases rapidly over the course of the kneading time after initial constancy. The effectiveness of the stabilizers is expressed in an extension of the

Constant time.

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Table 4

Parts stabilizer Time in 24 minutes
until change
of the torque None
0.15 part of pentaerythritol tetra- '
[3- (3,5-di-tert-butyl-4-hydroxy-
phenyl) propionate]
0.15 part of tris- (2-tert-butyl-
4-methylphenyl) phosphite.
0.05 part of pentaerythritol tetra-
{3- (3,5 ~ di-tert-butyl-4-hydroxy-
phenyl) propionate J.
+ 0.10 part tris-2-tert.-butyl-
4-methylphen3 ^T l) phosphite 2
6th
10 ^χ / 2

The data show that for the same total concentration the inventive combination to a clear one The result is a better protective effect compared to the stabilizers used individually.

Example IV. ■

100 parts mistabilisiertes P _o lyäthylen high density having a molecular weight of about 500 ¹ OOO ( "Lupolen 5260 Z ^lt powdered BASF) are each charged with 0.1 part of tris (tert 2-butyl-4-methylphenyl.) - phosphite and 0.05 part of the phenolic antioxidants of the following table 5. The mixtures are kneaded in a Brabender plastograph at 220 ° and 50 rpm for 20 minutes.

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During this time, the resistance is used as the torque continuously registered. As a result of cross-linking of the polymer takes place in the course of the kneading time after the initial Constancy a rapid increase in torque. The effectiveness of the stabilizers is expressed in an extension the constant time.

Table 5

Phenolic antioxidant Time in minutes
until change
of the instantaneous None ~ ■ 4th Pentaerythritol tetra- [3- (3,5-di-
tert-butyl-4-hydroxyphenyl) -pro-
pioneer - 10 ^χ / 2 l, l, 3 ~ Tris- (5-tert-butyl-4-
hydroxy-2-ir.ethylphenyl) butane 8th - 3- (3 _$ 5-di-tert-butyl-4-hydroxy-
phenyl) propionic acid octadecyl
ester 7th 1,3,5-tri- (3,5-di-tert-butyl-4-
hydroxybenzyl) -2,4,6-trimethyl-
benzene 8th 2,2'-MetlTylen-bis ~ (6-tert-butyl-
4-methy! Phenol) 10 methylphenol) 11

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The results show that with a wide range of phenolic compounds in combination with those according to the invention Triaryl phosphites provide excellent stabilization of high density polyethylene.

Example V

100 parts of unstabilized high density polyethylene having a molecular weight of about 500 ¹ OOO ( "Lupolen 5260 Z" in powder form from BASF) are dry blended with the listed in Table 6 stabilizers in the indicated concentrations. The mixtures are .During kneaded in a Brabender plastograph at 220 ⁰ C and 50 rpm for 20 minutes, this time the kneading resistance is recorded continuously as torque. As a result of the crosslinking of the polymer, there is a rapid increase in torque over the course of the kneading time after initial constancy. The effectiveness of the stabilizers is expressed in an extension of the constant time.

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Table 6

Effectiveness of the stabilizer correlations left according to the invention compared to the systems described in US 3,533,939.

Parts stabilizer Time in minutes until the change of the - 10 * • 12th D ehmomen t e s 0.05 parts 2,6-diter. butyl-4-methylphenol +0.1 part Tris- (2-tert. butyl-4-methylphenyl) - 5 phosphite 0.05 part 2, 6-liter. butyl-4-methylphenol 4th +0.1 part Tris- (2.4- ditert.butylphenyl) - phosphite 0.05 parts 2,6-diter. butyl-4-ynethylphenol + 0.1 part Polygard (Tris-p-nonylphenyl- phosphite) 0.15 parts Tris - (* 2-tert.- butyl-4-n: ethylphenyl) - phosphite

BO: - "! Y 3 6/0 9 6 8

ORIGINAL INSPECTED

Example VI

100 parts of unstabilized high density polyethylene having a molecular weight of about 500 ¹ OOO ( "Lupolen 5260 Z" in powder form from BASF) is mixed with 0.05 parts of 3- (3,5-di-tert-butyl-4-hydrox3 ^T phenyl) propionic acid ocfcadecyl ester and 0.1 part tris (2-tert.butyl-4-roethylph.enyl) phosphite mixed dry.

250 kg of this mixture are in an Extrusionsblasanlsge (Type VB 250 from Firtr.a VOITH) at 227 ° C DQsen temperature 120 liter barrels processed. (Frequency: IQ.minutes per Shot; 1 shot: 10 kg material). The barrels have a smooth inner surface and are free of lattice or honeycomb structures. ' Lattice or honeycomb structure or rough inner surface are the result of networking of the Materials.

Example VII

100 parts of polypropylene powder (Propathen HF 20 from ICI) are mixed homogeneously with the stabilizers listed in Table 7 below in the stated concentrations. The mixtures obtained are extruded 5 times in succession in a single-screw extruder at a maximum of 260 ° C. (temperature of the discharge zone) and 100 rpm and granulated. The melt index of the material is measured after the 1st, 3rd and 5th extrusion. The load is 2160 g at 230 ^° C., the melt index is given in g / 10 min. The degradation of the materisis manifests itself in an increase in the melt index.

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Table 7

Snow index by number
Extrusions 3 5 Parts stabilizer 1 42
6.5
8.0
* - *
5.0
4.9
4.5 76
9.0
12.3
7.4
6.6
⁶ \ ⁵ None
0.15 part of pentaerythritol tetra-
[3 - (. 3,5-di-tert-butyl-4-hydroxy-
phenyl) propionate]
0.15 part of tris- (2,4-di-tert.
butylphenyl) phosphite
0.075 parts penta'rythritol tetra-
[3- (3,5-di-tert-butyl-4-hydroxy-
phenyl) propionate]
+0.075 parts Tris- (2,4-di-tert.
butylphenyl) phosphite
0.05 part of pentaerythritol tetra-
[3- (3,5-di-tert-butyl-4-hydroxy-
phenyl) propionate]
+0.1 part Tris- (2,4-di-tert.
butylphenyl) phosphite
0.03 part of pentaerythritol tetra-
[3- (3,5-di-tert-butyl-4-hydroxy-
phenyl) propionate
+0.12 parts Tris- (2,4-di-tert.
butylphenyl) phosphite 14th
4.8
■ 4.0
= "3.5
^. 3.3
^ 3.2 6.8
4.5 ■ 9.0
6.2 0.15 parts 3,9-bis- [1,1-di-
methyl-2 (3,5-di-tert-butyl-4-
hydroxyphenyl) ethyl] 2,4,8,10-
tetraoxaspiro- [5.5] undecane
0.05 part 3,9-bis- [1,1-di-
methyl-2 (3,5-di-tert-butyl-4-
hydroxyphenyl) ethyl] 2,4,8,10-
tetraoxaspiro- [5.5] undecane
tO.l'.part Tris- (2,4-di-tert. ■
butylphenyl) phosphite 4.9
> 3.4

609B36 / 0-9 68

ORIGINAL INSPECTED

Claims (15)

Claims 1. Use of symmetrical triaryl phosphites of the general formula I ·. (D where · -. R-, ■ Lert.Butyl, 1,1-Dimethylprop} ^ !, Cyclohex3 ^T l or. . .Phenyl is and one of - - - R2 and Ro hydrogen and the other hydrogen, methyl, tert-butyl, 1,1-dimethylpropyl, cyclohexyl or Is phenyl, in combination with phenolic antioxidants for stabilization of polyolefins. 2. Use of symmetrical triaryl phosphites Claim 1, characterized in that in the formula I. R, tert-butyl and one of R ^ and R «is hydrogen and the other Denote hydrogen, methyl or tert-butyl. 3. Use of symmetrical tryaryl phosphites according to claim 1, characterized in that the phenolic Antioxidant is an ester of ß ~ (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid. 9 836/0968 26-0G358 4. Use of symmetrical triaryl phosphites Claim 1, characterized in that the phenolic antioxidant pentaerythritol tetra [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate is. 5. Use of symmestrischen triaryl phosphites according to claim 1, characterized in that the phenolic antioxidant β- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionic acid-n-octadec3 ⁷ 'is lester. 6. Veneering of symmetrical triaryl phosphites soaked Claim 1, characterized in that the phenolic antioxidant is a hydroxybenzyl aromatic. -7. Use of symmetrical triaryl phosphites according to claim 1, characterized in that the phenolic antioxidant is 1,3 ₅ 5-tri- (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene. 8. Use of symmetrical triaryl phosphites according to Claim 1, characterized in that the phenolic antioxidant 3,9-bis [1, l-dimethyl-2 (3,5-di-tert-butyl-4-hydroxyphenyl-ethyl] -2,4,8,10- tetraoxaspiro [5.5] undecane is, 9. Use of tris (2,4-di-tert-butylphenyl) phosphite according to claim 1, characterized in that the phenolic antioxidant 3,9-bis- [1,1-dimethyl-2 (3,5-di-tert. butyl-4-hydroxyphenyl-ethyl] -2,4,8,10-tetraoxaspiro- [5,5] -undecane is. 10. 'Use of symmetrical triaryl phosphites according to claim 1, characterized in that as an additional Additive stearyl alcohol is used. B Ο «36/0968 ^{UINAL INSP} <* H) 11. A method for stabilizing polyolefins, characterized in that one is a symmetrical triaryl phosphite of the general formula I according to claim 1 in combination with phenolic antioxidants according to claim 1 in incorporates the polymeric material. 12. Stabilizer system for polyolefins containing a phosphite of the formula I according to claim 1 and a phenolic one Antioxidant. 13. Polyolefins stabilized with a stabilizer system according to claim 12. 14. Polyethylene stabilized with a stabilizer system according to claim 12. 15. Polypropylene stabilized with a stabilizer system according to claim 12. 609836/0968 ORIQ ^ AL INSPECTED